Carbon saver for motion picture projectors



Feb. 28, 1956 D, OSTERHOUDT 2,736,836

CARBON SAVER FOR MOTION PICTURE PROJECTORS Filed 00C. 18, 1954 2 Sheets-Sheet l l6: 3% 12 A K) -40 37 DELMER D. OSTE BE I QgPT Feb. 28, 1956 D. D. OSTERHOUDT 2,736,836

CARBON SAVER FOR MOTION PICTURE PROJECTORS 2 Sheets-Sheet 2 Filed Oct. 18, 1954 DELMER D. OSTER H 0U 01' INVENTOR.

United States Patent CARBON SAVER FOR MOTION PICTURE PROJECTORS Delmer D. Osterhoudt, Des Moines, Wash. Application October 18, 1954, Serial No. 463,016

Claims. (Cl. 314-1) This present invention relates generally to the art of feed means for positive carbons as used in arc lights in the motion picture projectors. More particularly this invention relates to a device which is secured to a long unused positive carbon, and which facilitates the alignment and feeding of a short length of carbon. When this latter has been burned to the minimum usable length, means are provided for quickly displacing the stub and its holder and aligning the long carbon in arcing relationship with the negative carbon.

In the past many devices have been provided which had as their purpose the using up of lengths of carbon electrodes which had been burned to the minimum length practical with the more intricate feed means employed with the positive carbon. The devices that have been observed, however, have been characterized by being generally complicated in their structure so that they were costly. A further objection was that the parts of this equipment, which necessarily operate quite close to the are, soon became so damaged from the excess heat of the are that the cost of replacement of parts of the devices overweighed the savings made in the use of the short length of electrodes. In this present invention it is believed that a very worthwhile simplification of this equipment has been provided and one which maintains the functional parts of the device well out of the heat zone so that a long useful life can be assured for the parts making up the device; and thus, the main objective of such a device, which is an actual saving in over-all operating costs, can be easily eflected.

The principal object of my present invention therefore is to provide a carbon saving device which is characterized by its simplicity and economical construction.

A further object of my present invention is to provide a simple device that can be very quickly put into use and can be accurately adjusted with a minimum of time on the part of the operators.

A further object of my invention is to provide means whereby the burned down carbon stub can be displaced from its alignment with the negative carbon, and the new positive carbon introduced into arcing relationship with the negative so quickly that there is no notable diminishing of light on the screen to the average observer.

A further object of my invention is to provide alignment means for the carbons so'this device can be quickly clamped into position and then accurately adjusted'in any of the three planes required to insure axial alignment, and then to provide the means necessary to hold this adjustment during the operational range of the device.

Further objects, advantages and capabilities will be apparent from the description and disclosure in the drawings, or may be comprehended or are inherent in the device.

In the drawings:

Figure l is a side view of the essential elements of my invention showing a carbon stub in place and with certain of the associated mechanism common to projectors shown in dashed lines;

Figure 2 is a view taken in the same sense as Figure l and showing the carbon stub displaced from its operational position and with the long carbon in the position it as sumes when in alignment with the negative carbon;

Figure 3 is a figure similar to Figure 2 but illustrating the fully displaced position of the stub carbon holder and illustrating the manner in which it is well removed from the heat zone;

Figure 4 is a perspective view illustrating the portions of my device that are carried by the new carbon, which carbon is shown in dashed lines;

Figure 5 is a vertical end view looking at the crater end of the carbon and showing the elements of this invention;

Figure 6 is an exploded perspective view on the rest member and illustrating the three plane adjustments used with my equipment; and

Figure 7 is a small scale view of my equipment reduced substantially to a diagrammatic view in order to show the essential elements associated with my equipment.

Referring more particularly to the disclosure in the drawings, the numeral 10 designates generally the base clamp member of my device. This is made of two blocks 12 and 14 which are adapted to be clamped on to carbon C by means of the through bolt 16 and its associated wing nut 17. To form a secure engagement with carbon C blocks 12 and 14 are grooved throughout their length with grooves that are substantially, but not quite, semicircular. Pivotably secured to clamp 10 by bolt 16 is a third block 18. This block is spaced from the clamp proper by an enlarged portion of bolt 16 which is slightly longer than the thickness of block 18. This arrangement provides a shoulder which abuts block 14 and prevents any reduction of clearance between blocks 18 and 14, by pressure exerted by the wing nut 17. Free rotation of block 18 on bolt 16 is thus assured.

An electrical connection is made between clamp 10 and block 18 as by the flexible jumper 20 which is suitably secured at each of its ends as by standard U-connectors and suitable screws 22.

Fixedly secured to the pivoted block 18 is the stub carbon support rod 24. Support rod 24 is secured to block 18 in a manner permitting its ready removal, adjustment, or replacement, by means of the headless set screw 26. At the outer end of rod 24 is the stub carbon clamp indicated generally at 27 and which consists of the anchor block 28 which is fixedly secured, as by brazing, to rod 24. Coactive with block 28 is the clamp block 30. Blocks 28 and 30 are grooved so as to accept the stub carbon 32 and the same is held in clamped relationship by preferably a cap screw 34.

The upper surface of clamp members 27, 30 is grooved or Vd at 36 so as to provide a rest for carbon C in the same vertical plane as carbon stub 32.

To insure axial positioning and the maintenance of axial alignment of the positive carbon with the negative carbon, I provide a rest member 40. This rest member is grooved at 42 to accept either the long carbon C or the stub carbons 32. Rest member 40 is fixedly secured by any convenient means, as by bolting thereto, or welding, to the base plate 44. This base plate is provided with an elongated opening or slot 46 to the end that the base plate and the rest member can be adjusted longitudinally of the axis of the carbons. The base plate 44 is supported by an anchor member 43. This member is secured to one of the elements of the projector as is indicated at 50 in Figure l or 7. The anchor is preferably secured to member 50 by two screws passing through vertically extending slots as 52 and 53 to the end that vertical adjustment may be made which will permit, in turn, the vertical adjustment of rest member 49. A secondary rest member 60 completes this unit. This memher is provided. with preferably a sloping rest surface 62 adapted to arrest the downward movement of the stub carbon carrier when it is displaced and the long carbon brought into use. The inwardly sloping surface 62 tends to definitely p 'on this assembly. As will be noted in Figure 6, base plate 44, rest anchor member 53, and the secondary rest member 69, are secured in operating relationship by a single screw which is tapped into block 43 and then passed through slots and 6. With this arrangement it will be apparent, it is believed, quite liberal adjustment of ti e position of these parts can easily clfected and. thus this equipment can be readily adapted to existing equipment which often varies substantially in dimensions as the equipment is modified or improved by the manufacturers of the projectors.

Operation in use a use, clamp 19 is When this ccniipnicnt is put i to secured to the supporting end of the long carbon k, adjacent its feed mechanism 7%. This supporting and feed mechanism takes on many forms as produced by the various nanufacturcrs forms no part of this present invention. is then adjusted with respect to clamp it) by loosening set screw 26, and adjusting the position the outer stub clamp 27 with respect to the using end c en burned. minimum length, its crater end will be in g t with the end of carbon C. This is an essential adjustment in order that a quick transfer can be made from one carbon to the other and not interfere with the lighting on the him being projected. To insure a proper angular relationship and to provide that carbon stub 32 will be parallel in usi. position to carbon C, rod 24 is provided with a straight portion 25 of sufficient length to accommodate this adjustment. Rod 2-iis then suitably bent to engage block 23, preferably parallel to carbon 32. As the stub carbon is burned before switching to new carbon C,' the starting position will be that indicated in Figure l which stub carbon 32 is positioned within the groove of member in use this present carbon 32 is fed into the arc the holder and feed mechanism 7%, ji.t as though it were the long carbon. this position tne current how is through carbon "C. through cc motor 2%), out rod 2 5, to the carbon holder 26. This fo ms a very positive path for the supplying of electric current to these arcs.

It will be noted that the form or clamp member 27 is such that both members 28 ab 33 a within guide groove of rest member As the feed progresses to the point where clamp her 2/ pas es over and just beyond rest member the clamp meitzocr drops of its own weight, in so doing lowers the long carbon to provide a continua- "t tion of the arc. As the stub carbon (lCl and the new carbon are associated quite else i the time interval of its transfer is usua ly 0 so duration Conseauen through the projector.

loss of light on the it is to that the fa side of rest member 4 is angularly disposed will b noted at ll. This is to insure that. clamp 27, in dropping out of its position of use, will not hang up on the forward edge of the rest member as it would otlrruise do, due to the fact that it is pivoted to clamp i through biocl' "El and therefore must travel in the are provided by the used length of rod 2%. Carbon C which is clamped in mechanism 7% pivots about center 7 during cha z'e of position.

It is belie'ed that it will be clearly j t from the above description and the disclosure in the drawings that the invention comprehends a novel construction of a carbon saver for motion picture projectors.

Having thus disclosed the invention, I claim:

1. A positive carbon holder for an arc projector, comprising: a base block formed by a pair of juxtaposed plates having aligned recesses on their adjacent surfaces and a long carbon having one end portion positioned in said recesses and a clamp bolt in said block clamping said plates to said long carbon, one end portion of said bolt being of increased diameter abutting one of said plates and a pivoting block mounted on the enlarged portion of said bolt alongside said main block, said pivoting block having an arm extending therefrom having a bend in its central portion and straight end portions and a stub carbon block secured to the other end of said rod, said stop block being formed by a pair of juxtaposed clamping members and having a V rest on its upper surface in which said long carbon is received, a stub carbon and said clamp members having aligned recesses on their inner faces clamping the end of said stub carbon extending beyond the end of said long carbon, a rest member positioned below said stub carbon and having a groove in its upper surface in which said stub carbon rests for sliding movement toward the negative carbon and the lower surfaces of said clamp members being chamfered to slide through said groove and said long carbon being positioned to fall into said groove as said stub carbon and stub block pass said groove and fall, said rest member having secured to its lower end a horizontal base plate extending to one side thereof and a base member adapted to be secured to such projector on which the second end of said base plate rests, said second end of said base plate having an elongated slot and a bolt tapped into said base member and extending through said elongated slot and a secondary rest member extending horizontally laterally of said first base member and having an elongated slot in which said bolt is positioned and the end of said secondary base member having an inwardly sloping top rest surface to accept said stub block and rod as the stub block falls from said groove.

2. A positive carbon holder for are projectors, comprising: a main block adapted to clamp the end portion of a long carbon adjacent a positive carbon feeding mechanism, a rod having one end portion pivotally secured to said main block and extending alongside the axis of such long carbon, a stub block at the other end of said rod and adapted to support a stub carbon extending beyond such long carbon, a rest formed on said stub block to accept the free end portion of said long carbon, 2. rest assembly including a base block adapted to be secured to a portion of such projector below said stub carbon, at base arm having an elongated slot in one end and a bolt tapped in the upper end of said base member and positioned in said elongated slot whereby said base arm may be adjusted by sliding movement relative said bolt and by pivoting therearound, an inverted frustopyramidal block positioned on the other end of said base arm and upstanding therefrom and having a rest groove positioned to accept such stub carbon and to support the same in sliding movement toward the negative carbon and disposed to receive such long carbon when said stub, carbon and stub block have moved past said groove and have fallen therefrom.

3. The subject matter of claim 2 in which there is a secondary base plate extending laterally of said base arm and having an elongated groove in which said bolt is positioned and having at its end opposite said elongated groove an inwardly slanting upper surface disposed to support, the stub block and arm as the stub block falls from said groove.

4. A positive carbon holder for a projector, comprising: a main block having a. pair of juxtaposed plates having aligned juxtaposed grooves in their adjacent faces to clamp the end portion of a long carbon adjacent a positive car bon feeding mechanism and a clamping bolt extending through said plate and having a nut on one end, the

Iarged portion of said bolt alongside said main block, an arm extending alongside the axis of such long carbon from said pivoting block and a stub block secured to the other end of said rod and having a rest on its upper surface disposed to accept the other end of said long carbon, said stub block having a pair of juxtaposed clamp members having complementary grooves in their adjacent lower surfaces to accept the end of a stub carbon extending beyond such long carbon, a base rest adapted to be secured to such projector below such stub carbon and having a groove in its upper surface disposed to accept such stub carbon in its initial position and said clamp members having chamfered lower surfaces so as to slide through said groove as the assembly is advanced by the positive feeding mechanism, and said groove being disposed to accept such long carbon as the stub carbon and stub block are moved past the grooves to fall from said base rest.

5. A device for holding the positive carbon of a projector, comprising: a base block having clamp means adapted to clamp a long carbon adjacent a positive carbon feed mechanism, an arm extending alongside the axis of such long carbon and having one end pivotally secured to said main clamp member and having on its other end a stub carbon clamp block adapted to clamp a stub carbon extending beyond the end of the long carbon, said stub block having a rest formed on its upper surface to support the adjacent end portion of such long carbon, a rest member adapted to be secured to the projector assembly beneath the location of such stub carbon and having a groove on its upper end adapted to support such stub carbon, and, as said feed mechanism advances the long carbon, the groove forming a guide for the stub carbon and stub carbon block until they pass the rest member at which point the stub carbon block will drop and such long carbon will fall into place on said rest.

No references cited. 

